Math question!

Test Preparation SAT Preparation
1

<p>I got D but my answer key says E. </p>

<p>Why is E correct? </p>

<p><a href="http://i.imgur.com/R7IcT.png%5B/url%5D"&gt;http://i.imgur.com/R7IcT.png&lt;/a&gt;&lt;/p>

2

<p>Odd is a discriminated set of numbers.</p>

<p>Only odd * odd can yield odd.</p>

<p>In order for xyz to be odd, x, y and z must be odd.</p>

3

<p>Only I is correct because II and III are not necessarily MUSTs, so none of the answers are correct. Since multiplication is interchangeable… y could be negative, odd and x, z could be positive, odd and it would still be a negative odd integer.</p>

4

<p>hmmm I see what the above poster is saying, but remember they just asked which of the following must be true, not which of the following is the only truth. so to satisfy the question then, form the following, I, II and II must be true.</p>

5

<p>Must means that it absolutely has to be true, otherwise it wouldn’t work. II and III together COULD be true, but it definitely isn’t an underlined MUST like the question had it.</p>

6

<p>I, II and III MUST be true.</p>

<p>Semaphore12, can you provide an example of when II is not true?</p>

7

<p>I II and III all must be true.
I is true because the only way to get an odd number by multiplying 3 numbers together is to start with 3 odds.
II and III are true because, remember, x y and z are on a number line, so x MUST be the smallest number. Either one or all three of the numbers must be negative, so the smallest MUST be negative, and the next 2 MUST be either negative<em>negative is always >0 or positive</em>positive is always >0</p>

8

<p>^ This (10 char)</p>

9

<p>I made it out of order for your benefit~ :)</p>

<p>x<y<z</p>

<p>II) X HAS TO be negative for this occurrence, because x is LESS than both Y and Z… so if Y is negative x is negative and if Z is negative, Y is negative and X is negative. II is correct</p>

<p>I) -7<7<13 now (-7)(7)(13) Correct. or put in any odd integers with x being negative
III) If Z is positive and IF Y is negative and X HAS to be negative, then the integer becomes positive because of two negative numbers being multiplied or… we see that (+Z)(-Y) IS NOT greater than 0</p>

<p>The only two possible solutions are
(+Z)(+Y)>0
(-Z)(-Y)>0
so III is correct
therefore II is true…
so is I…</p>

<p>Answer: E</p>